如何以編程方式將項目符號列表添加到NSTextView

Question

這個問題可能聽起來很奇怪，但我已經掙扎了好幾天了。

我有一個NSTextView，可以顯示一些帶有一些格式選項的文本。 其中之一是能夠為選擇或當前行打開/關閉子彈列表（最簡單的一個）。

我知道在NSTextView上有一個orderFrontListPanel：方法打開窗口，其中包含可供選擇和編輯的可用列表參數（例如，當您按Menu-> Format-> List ...時在TextView中）。 我已經想出並實現了手動添加項目符號，NSTextView似乎幾乎正確地使用它們。 通過說幾乎我的意思是它保留標簽位置，繼續“輸入”列表，等等。但是有一些小故障不適合我，不同於標准實施。

我試圖找到以編程方式設置列表的默認方式，就像通過“列表...”菜單完成一樣沒有運氣。

我請求幫助，每一點點的信息都會受到贊賞:)。

PS：我已經查看了TextView源代碼，發現了很多有趣但沒有跡象或線索如何以編程方式啟用列表。

更新

還在調查。 我發現當你發送orderFrontListPanel：到你的NSTextView然后選擇項目符號並按回車鍵時，沒有特殊的消息被發送到NSTextView。 這意味着可以在彈出式面板中的某處構建項目符號列表，並直接設置為TextView的文本容器...

Answer 1

以編程方式將項目符號列表添加到NSTextView的兩種方法：

方法1：

以下鏈接引導我使用第一種方法，但除非您想為子彈使用一些特殊的非Unicode字形，否則它是不必要的回旋：

• 在NSTextView中顯示隱藏的字符
• 如何繪制一個沒有unicode表示的NSGlyph？
• appendBezierPathWithGlyph在[NSBezierPath currentPoint]中失敗

這需要：（1）子類化布局管理器，用子彈字形替換某些任意字符; （2）帶有firstLineHeadIndent的段落樣式，比該縮進略大的制表位，以及用於組合兩者的包裹線的headIndent。

布局管理器如下所示：

#import <Foundation/Foundation.h>

@interface TickerLayoutManager : NSLayoutManager {

// Might as well let this class hold all the fonts used by the progress ticker.
// That way they're all defined in one place, the init method.
NSFont *fontNormal;
NSFont *fontIndent; // smaller, for indented lines
NSFont *fontBold;

NSGlyph glyphBullet;
CGFloat fWidthGlyphPlusSpace;

}

@property (nonatomic, retain) NSFont *fontNormal;
@property (nonatomic, retain) NSFont *fontIndent; 
@property (nonatomic, retain) NSFont *fontBold;
@property NSGlyph glyphBullet;
@property CGFloat fWidthGlyphPlusSpace;

@end

#import "TickerLayoutManager.h"

@implementation TickerLayoutManager

@synthesize fontNormal;
@synthesize fontIndent; 
@synthesize fontBold;
@synthesize glyphBullet;
@synthesize fWidthGlyphPlusSpace;

- (id)init {
    self = [super init];
    if (self) {
        self.fontNormal = [NSFont fontWithName:@"Baskerville" size:14.0f];
        self.fontIndent = [NSFont fontWithName:@"Baskerville" size:12.0f];
        self.fontBold = [NSFont fontWithName:@"Baskerville Bold" size:14.0f];
        // Get the bullet glyph.
        self.glyphBullet = [self.fontIndent glyphWithName:@"bullet"];
        // To determine its point size, put it in a Bezier path and take its bounds.
        NSBezierPath *bezierPath = [NSBezierPath bezierPath];
        [bezierPath moveToPoint:NSMakePoint(0.0f, 0.0f)]; // prevents "No current point for line" exception
        [bezierPath appendBezierPathWithGlyph:self.glyphBullet inFont:self.fontIndent];
        NSRect rectGlyphOutline = [bezierPath bounds];
        // The bullet should be followed with a space, so get the combined size...
        NSSize sizeSpace = [@" " sizeWithAttributes:[NSDictionary dictionaryWithObject:self.fontIndent forKey:NSFontAttributeName]];
        self.fWidthGlyphPlusSpace = rectGlyphOutline.size.width + sizeSpace.width;
        // ...which is for some reason inexact. If this number is too low, your bulleted text will be thrown to the line below, so add some boost.
        self.fWidthGlyphPlusSpace *= 1.5; // 
    }

    return self;
}

- (void)drawGlyphsForGlyphRange:(NSRange)range 
                        atPoint:(NSPoint)origin {

    // The following prints only once, even though the textview's string is set 4 times, so this implementation is not too expensive.
    printf("\nCalling TickerLayoutManager's drawGlyphs method.");

    NSString *string = [[self textStorage] string];
    for (int i = range.location; i < range.length; i++) {
        // Replace all occurrences of the ">" char with the bullet glyph.
        if ([string characterAtIndex:i] == '>')
            [self replaceGlyphAtIndex:i withGlyph:self.glyphBullet];
    }

    [super drawGlyphsForGlyphRange:range atPoint:origin];
}

@end

將布局管理器分配給窗口/視圖控制器的awakeFromNib中的textview，如下所示：

- (void) awakeFromNib {

    // regular setup...

    // Give the ticker display NSTextView its subclassed layout manager.
    TickerLayoutManager *newLayoutMgr = [[TickerLayoutManager alloc] init];
    NSTextContainer *textContainer = [self.txvProgressTicker textContainer];
    // Use "replaceLM" rather than "setLM," in order to keep shared relnshps intact. 
    [textContainer replaceLayoutManager:newLayoutMgr];
    [newLayoutMgr release];
    // (Note: It is possible that all text-displaying controls in this class’s window will share this text container, as they would a field editor (a textview), although the fact that the ticker display is itself a textview might isolate it. Apple's "Text System Overview" is not clear on this point.)

}

然后添加一個類似這樣的方法：

- (void) addProgressTickerLine:(NSString *)string 
                   inStyle:(uint8_t)uiStyle {

    // Null check.
    if (!string)
        return;

    // Prepare the font.
    // (As noted above, TickerLayoutManager holds all 3 ticker display fonts.)
    NSFont *font = nil;
    TickerLayoutManager *tickerLayoutMgr = (TickerLayoutManager *)[self.txvProgressTicker layoutManager];
    switch (uiStyle) {
        case kTickerStyleNormal:
            font = tickerLayoutMgr.fontNormal;
            break;
        case kTickerStyleIndent:
            font = tickerLayoutMgr.fontIndent;
            break;
        case kTickerStyleBold:
            font = tickerLayoutMgr.fontBold;
            break;
        default:
            font = tickerLayoutMgr.fontNormal;
            break;
    }


    // Prepare the paragraph style, to govern indentation.    
    // CAUTION: If you propertize it for re-use, make sure you don't mutate it once it has been assigned to an attributed string. (See warning in class ref.)
    // At the same time, add the initial line break and, if indented, the tab.
    NSMutableParagraphStyle *paragStyle = [[NSParagraphStyle defaultParagraphStyle] mutableCopy]; // ALLOC
    [paragStyle setAlignment:NSLeftTextAlignment]; // default, but just in case
    if (uiStyle == kTickerStyleIndent) {
        // (The custom layout mgr will replace ‘>’ char with a bullet, so it should be followed with an extra space.)
        string = [@"\n>\t" stringByAppendingString:string];
        // Indent the first line up to where the bullet should appear.
        [paragStyle setFirstLineHeadIndent:15.0f];
        // Define a tab stop to the right of the bullet glyph.
        NSTextTab *textTabFllwgBullet = [[NSTextTab alloc] initWithType:NSLeftTabStopType location:15.0f + tickerLayoutMgr.fWidthGlyphPlusSpace];
        [paragStyle setTabStops:[NSArray arrayWithObject:textTabFllwgBullet]];  
        [textTabFllwgBullet release];
        // Set the indentation for the wrapped lines to the same place as the tab stop.
        [paragStyle setHeadIndent:15.0f + tickerLayoutMgr.fWidthGlyphPlusSpace];
    }
    else {
        string = [@"\n" stringByAppendingString:string];
    }


    // PUT IT ALL TOGETHER.
    // Combine the above into a dictionary of attributes.
    NSDictionary *dict = [NSDictionary dictionaryWithObjectsAndKeys:
                            font, NSFontAttributeName, 
                            paragStyle, NSParagraphStyleAttributeName, 
                            nil];
    // Use the attributes dictionary to make an attributed string out of the plain string.
    NSAttributedString *attrs = [[NSAttributedString alloc] initWithString:string attributes:dict]; // ALLOC
    // Append the attributed string to the ticker display.
    [[self.txvProgressTicker textStorage] appendAttributedString:attrs];

    // RELEASE
    [attrs release];
    [paragStyle release];

}

測試出來：

NSString *sTicker = NSLocalizedString(@"First normal line of ticker should wrap to left margin", @"First normal line of ticker should wrap to left margin");
[self addProgressTickerLine:sTicker inStyle:kTickerStyleNormal];
sTicker = NSLocalizedString(@"Indented ticker line should have bullet point and should wrap farther to right.", @"Indented ticker line should have bullet point and should wrap farther to right.");
[self addProgressTickerLine:sTicker inStyle:kTickerStyleIndent];
sTicker = NSLocalizedString(@"Try a second indented line, to make sure both line up.", @"Try a second indented line, to make sure both line up.");
[self addProgressTickerLine:sTicker inStyle:kTickerStyleIndent];
sTicker = NSLocalizedString(@"Final bold line", @"Final bold line");
[self addProgressTickerLine:sTicker inStyle:kTickerStyleBold];

你得到這個：

方法2：

但子彈是一個常規的Unicode字符，在十六進制2022.所以你可以直接把它放在字符串中，並得到一個精確的測量，如下所示：

    NSString *stringWithGlyph = [NSString stringWithUTF8String:"\u2022"];
    NSString *stringWithGlyphPlusSpace = [stringWithGlyph stringByAppendingString:@" "];
    NSSize sizeGlyphPlusSpace = [stringWithGlyphPlusSpace sizeWithAttributes:[NSDictionary dictionaryWithObject:self.fontIndent forKey:NSFontAttributeName]];
    self.fWidthGlyphPlusSpace = sizeGlyphPlusSpace.width;

因此不需要自定義布局管理器。 只需像上面那樣設置paragStyle縮進，並將文本字符串附加到一個字符串，該字符串包含return + bullet char + space（或者+ tab，在這種情況下，您仍然希望該制表符停止）。

使用空格，這產生了更嚴格的結果：

想要使用子彈以外的角色嗎？ 這是一個很好的Unicode圖表： http ： //www.danshort.com/unicode/